recovering in noarchive log mode while redo logs are not overwritten

Here is an excerpt from offical Oracle material:

For a database in noarchivelog mode, you do not have to restore all Oracle files if no redo log file has been over-written since the last backup.

Scenerio:
- There are two redo logs for a database
- A closed database backup was taken at log sequence 144.
- While the database was at log sequence 145, datafile 2 was lost

Result:
Since log sequence 144 has not been over-written, just datafile number 2 can be restored and recovered manually.
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My question is: after restoring datafile #2, it has log sequence 144 while the other files have 145. Do I need to mount it and use "recover" command to bring it up to 145, or it is done automatically when I do "startup"?

Thanks!

yes.

You have to mount database and recover datafile. then open database.